Graphics card (AMD): https://preisvergleich.pcgameshardware.de/asus-arez-strix-radeon-rx-vega-56-oc-gaming-90yv0b53-m0na00-a1840662.html?hloc=at&hloc=de
Graphics card (Nvidia): https://preisvergleich.pcgameshardware.de/kfa-geforce-rtx-2060-1-click-oc-26nrl7hpx7ok-a1961909.html?hloc=at&hloc=de
Processor: http://preisvergleich.pcgameshardware.de/amd-ryzen-5-2600-yd2600bbafbox-a1804462.html
Mainboard: http://preisvergleich.pcgameshardware.de/asrock-b450m-pro4-90-mxb8f0-a0uayz-a1858732.html?hloc=at&hloc=de
CPU cooler: http://preisvergleich.pcgameshardware.de/arctic-freezer-33-acfre00028a-a1589294.html
Main memory: http://preisvergleich.pcgameshardware.de/g-skill-aegis-dimm-kit-16gb-f4-3000c16d-16gisb-a1474853.html?hloc=at&hloc=de
Power supply: http://preisvergleich.pcgameshardware.de/be-quiet-pure-power-11-cm-500w-atx-2-4-bn297-a1910266.html?hloc=at&hloc=de http://preisvergleich.pcgameshardware.de/seasonic-focus-plus-gold-650w-atx-2-4-ssr-650fx-a1658737.html (Radeon); http://preisvergleich.pcgameshardware.de/be-quiet-pure-power-11-cm-500w-atx-2-4-bn297-a1910266.html?hloc=at&hloc=de (Geforce)
SSD: http://preisvergleich.pcgameshardware.de/crucial-mx500-500gb-ct500mx500ssd1-a1745351.html?hloc=at&hloc=de
How much FPS would that achieve and would Fortnite run smoothly?
What should I change for up to 100 fps
FPS depend on the game and the settings used.
But Fortnite should run at 100fps in most scenarios.
And please think of a suitable (100hz +) screen.
What should I change for up to 100 fps
You decide for a graphics card. It does not bother you to have two different ones in the PC.
Looks good!
For Fortnite, I would choose the RTX 2060, because that is much better with the Nvidia cards. There are umpteen videos showing the FPS.
To the power supply: Both would suffice 500W, I would still choose the Seasonic, since the 10-year warranty offers! Otherwise, even a 400W Pure Power 11 is sufficient for the RTX 2060. I would prefer to go here but on the 500W, if you want to upgrade times.
Yes, I only want one, but which of the two
The Vega 56.
At the top of the comment, one prefers to say the RTX 2060
Can you take a good Intel processor instead of AMD?
What they say refers only to Fortnite. Since you certainly do not just play Fortnite, I recommend the Vega 56.
There's nothing wrong with the Ryzen 5 2600, but of course you can also rely on an Intel processor. Unfortunately, Intel has no CPU in the price range as a "competitor".
For pure gaming (no streaming or video editing) you could still take the Intel i5 9600K, but it costs 250 euro and a good motherboard 100-150 euro.